Some well known songs consist of only one or two sections, for example "Jingle Bells" commonly contains verses ("Dashing through the snow...") and choruses ("Oh, jingle bells..."). It may contain "auxiliary members" such as an introduction and/or outro, especially when accompanied by instruments (the piano starts and then: "Dashing...").

A section is, "a major structural unit perceived as the result of the coincidence of relatively large numbers of structural phenomena." An episode may also refer to a section.

A passage is a musical idea that may or may not be complete or independent. For example, fill, riff, and all sections.